1. Technical Field
The present invention relates to a high efficiency Plasma Display Panel (PDP).
2. Related Art
A front panel of an alternate type three electrode surface discharge PDP comprises a front substrate, sustaining electrode pairs including Y electrodes and X electrodes formed on the rear surface of the front substrate, a front dielectric layer covering the sustaining electrode pairs, and a protection film covering the front dielectric layer. Each of the Y electrodes and X electrodes includes transparent electrodes and bus electrodes. The bus electrodes are connected to connecting cables on the left and right sides of the PDP.
A rear panel of an alternate type three electrode surface discharge PDP comprises a rear substrate, address electrodes crossing the sustaining electrode pairs on the front surface of the rear substrate, a rear dielectric layer covering the address electrodes, barrier ribs formed on the rear dielectric layer to define discharge cells, and fluorescent layers in the discharge cells. The address electrodes are connected to connecting cables on the upper and lower surfaces of the PDP.
The above-noted PDP has the problem of reduced transmission of visible light from the fluorescent layers in the discharge cells, since the sustaining electrode pairs causing a discharge, the front dielectric layer, and the protection film are formed on the rear surface of the front substrate, thereby reducing the brightness of the PDP.
Also, all of the sustaining electrode pairs except the bus electrodes are formed of ITO electrodes, which have a high resistance, since the sustaining electrode pairs causing a discharge are formed on the rear surface of the front substrate. This increases the operating voltage. Also, when the PDP is large, the high resistance of the ITO electrodes causes a voltage drop in the sustaining electrode pairs. This results in non-uniform images of the PDP.
Also, in the PDP, the discharge occurs at the rear of the protection film in the discharge cells, since the sustaining electrode pairs causing a discharge are formed on the rear surface of the front substrate through which the visible light passes. The occurrence of discharge on one surface among inner surfaces of the discharge cell reduces light emitting efficiency. Also, when the PDP is operated for a long time, charged particles accelerated by the electric field can cause an ion sputtering problem on the fluorescent layers by colliding with the fluorescent layers 125, thereby causing a permanent latent image.
In the PDP, a pulse voltage is applied to the address electrodes and the X electrodes. This results in a potential difference between the address electrodes and the X electrodes to generate a discharge. The discharge generates a wall charge on the rear surface of the protection film of a particular discharge cell. When an electric potential difference lower than the electric potential difference between the address electrodes and the X electrodes is generated alternately in the sustaining electrode pair, an electric potential difference greater than a predetermined firing voltage is generated on the rear surface of the protection film with the aid of the wall charge, causing a sustaining discharge. The wall charge is accumulated on the rear surface of the protection film by the pulse voltage applied to the sustaining electrode pair. From this result, a displacement current Iad flows between the X electrodes and the protection film and between the Y electrodes and the protection film. On the other hand, a pulse voltage is alternately generated between the sustaining electrode pair in the front dielectric layer, and a displacement current Iam flows since the pulse voltage changes according to time. The displacement current Iam does not contribute to forming the wall charge but is consumed as reactive power. The consumption of reactive power includes reactive power formed by the displacement current caused by the potential difference which changes according to time and flows in the dielectric, and power consumption caused by heat generated by a non-ideal dielectric. The consumption of the reactive power eventually increases the operating voltage of the PDP and reduces efficiency.